1. Field of the Invention
The present invention relates to an image forming apparatus that stores a print job in a memory area, a method of controlling the image forming apparatus, and a storage medium, and more particularly to a job control technique for an image forming apparatus, which makes it possible perform reservation printing even in a state of a memory area in which a free space thereof for storing data of a print job is insufficient.
2. Description of the Related Art
In recent years, an image forming apparatus has come to be used which is equipped with an auxiliary memory, such as a hard disk, and has a function of reservation printing in which data of a print job is stored in the auxiliary memory, and the print job is printed out based on the stored data thereof at a desired time. In this image forming apparatus, unless access control is carried out for the data of the print job stored in the auxiliary memory, any user can print out the data of this print job, and hence it is undesirable from the viewpoint of security. To solve this problem, there has been proposed an authentication-linked reservation printing system in which reservation printing is performed by associating a user of an image forming apparatus and an owner of stored data with each other (see e.g. Japanese Patent Laid-Open Publication No. 2008-265341).
On the other hand, in a case where the image forming apparatus is operated in a forcible reservation mode in which the aforementioned reservation printing is forcibly executed, if the free space of the auxiliary memory becomes insufficient, not only printing but also storage of data of a print job for reservation itself cannot be executed, and hence it is undesirable from the viewpoint of user-friendliness. To solve this problem, there has been proposed an image forming apparatus capable of increasing the free space of the auxiliary memory by compressing old data stored therein (see e.g. Japanese Patent Laid-Open Publication No. H06-105098).
A combination of the methods disclosed in Japanese Patent Laid-Open Publication No. 2008-265341 and Japanese Patent Laid-Open Publication No. H06-105098 makes it possible to construct a reservation printing system in which a print job stored in an auxiliary memory is associated with an owner of the job, and the free space of the auxiliary memory can be increased by compressing old data stored therein when the free space becomes insufficient.
However, according to this reservation printing system, it is impossible to increase the free space when all data items stored in the auxiliary memory have already been compressed. Further, even if the free space can be increased in the above-described manner, there can occur a case where data of a print job of another user is stored in the increased free space area, and this sometimes makes it impossible to store the data of the user's own print job. Particularly, in an environment in which the image forming apparatus is operated in the above-mentioned forcible reservation mode, if the free space of the auxiliary memory is exhausted, the image forming apparatus becomes incapable of executing either reservation of a print job or printing thereof.